decklid mock-up photos

[moonmonkey]

im about to take a 1000 mile trip for work i want this on before i go. will this help my wake , im raising it up 2.25 inches higher than the trunk lid but sealing it so no air flows between the trunk and decklid, my trunk has a slight downward slope but i was going to make the lid level with the horizon, when its level it sticks out 14 inches behind the car at 15 degrees from my roofline to the back of the deck lid. if i read Hucho correctly both riasing and extending the deck sould help aero? am i on the right track? any pointers before i make this thing out of wood/lexan for the trip ? like angle- and do i need the vertical peices on each side like the fusion 999 flats racer? help a aero retard out, i got the ecomodd bug bad.

[alohaspirit]

the angle looks pretty good

you could also get a hitch and attach an extender
then temporary tarp it from the rear window
http://ecomodder.com/forum/showthrea...sts-10725.html

that commute is truly a killer. id die.
(mine is 4 miles)

[moonmonkey]

my daliy commute is 105 miles round trip, but i go to our other stores a few times a year i usally put 1000- 1400 miles when i go from fl- to raliegh NC. I would hate it to if it were more often.

[Christ]

I wouldn't go with 15* unless you drive slower than 60-65 for the whole trip, you'll likely find that it's too steep.

If I get what you're saying, you basically want to build a Kamm back that is just an extension from the window/roof area, but ends past the deck lid?

As per usual, I always suggest about 12-13 degrees for a DIY project without access to a wind tunnel or a person just wanting to "test everything out" as it were.

Of course, that will put you out a bit further, and you're probably going to lose visibility through the rear window, something to consider... most clear materials distort at that angle, so everything will probably be a colored shadow that you can't really make out very well.

Don't forget to taper in the sides some, at least to match the tail of the car.

[Christ]

Also, it will help less, but it will still help if you terminate your extension over top the deck lid, rather than extending it 14+ inches further.

Whichever route you take, make sure you have a clean edge for the flow to separate.

[Frank Lee]

I disagree.

As in the example of the racing Fusion, going "out back" instead of up should reduce the area of the rear of the vehicle that experiences turbulence MORE than going "up", hence it should be a more effective drag reducer and fe increaser. After all, if the rear edge of this extension (no matter if it goes up and/or back) goes out to the "template", the rear window/over the trunk zone should "see" decent flow as in pickups with tonneaus.

I would go so far as to say, don't raise the lid at all, just go back... but it may have to go back unacceptably far to reach the template outline... THAT is when you consider raising it.

[Christ]

Frank, what are you disagreeing with?

I said "it will help less, but will still help [...] "

I think you misread something.

[Frank Lee]

Oh- I did re-read.

Not so much disagree, but clarify: He doesn't want to build a Kamm; he wants a spoiler like that salt flats Fusion.

[Christ]

That's where I'm wondering. I don't see actual mention of making a Kamm extension, but that's the appearance from the photos. Of course, the description says decklid extension, so yeah.

In that case, a pure extension would help more, and an extension trained downward would help even more, by training flow downward before it detaches, helping to lessen the wake area.

[Frank Lee]

Yes- angled down should be even more effective.

I was doing similar mocking up on the Tempo for the Fusion style extension... aesthetically, a straight-back one with endplates says "boy racer" which I can live with, and it went back, oh, 14" or so. The droopy one might be a tougher sell, aesthetically, and it would really stick way out the back...